Hello pilots

While a lot of people are chasing to get FMS for 737, I found it very impressive to do VOR arrivals and approaches combined with ILS. But what I have noticed, that I was making them "partly blind". While established on ILS and already on a glide slope, I do not have any DME reading for it. I did it in many different airports and even started to check that ILS really does have DME. As for example Frankfurt international does have it on all runways in P3D V4.5, but my DME always shows nothing. It is operational when tuned to VOR DME, but not ILS.
Is there something I am doing wrong? Need to mention I have installed "total overhaul" from avsim library and it works fine for me, so it's hard to believe there is a mistake in that. I really hope it's just some switch that I don't know or forget to switch on... 

Regards, Viktor.

Thank you Markoz for taking your time, appreciate it.
Now I am confused a little. I guess it's Deja Vu 
I have navigraph subscription and use their charts for flying and on all of the runways it says ILS DME. But P3D V4.5 is not supported by navigraph and very often frequencies are different in the simulator than in the charts. Not a big problem, just need to check frequencies in the sim map before flying. Anyway Frankfurt airport is a little bit strange. As in real world and on charts it has 3 runways 25. L, C and R. But in P3D there is runway 26L also, which is not a separate runway, but some kind of extension to runway 25 L. And there is actually two sets of PAPI lights and even marking 26L further on the runway Well, doesn't matter, if it also doesn't show distance for you, then it's definitely not problem with plane or total overhaul and I am happy. Just curious, is this normal in real world not always have DME reading for ILS? How to know then how far you are from the runway? I always tune to some local VOR on second NAV, but it's not an exact reading as it can be located in any position related to runway. Or just need to trust GS and radio altimeter?

Ah those sim makers... They think for us it's game, they don't know how professional we really are and how important simulation of real world is for us 
Out of the topic, need to say, that "total overhaul" is a really good thing. I like improved cabin lightning and functionality of PDCS. It helps flight planning a lot and has some other useful features. Recommend to try if you didn't yet.
As for ILS DME and other navigational aids, I know that navigraph is supporting FS and a lot of other pay ware products. So their data manager can be used to update those. And if it really updates everything as it is per their charts, than it is really worth the money. Unfortunately they do not support P3D and CS 737 and it's sad. But I am thinking to move to MSFS in near future as I heard it is really good and navigraph supports that. Only waiting for pay ware aircraft to be available for that sim as there not much at the moment. And I really hope CS is also working hard on that and will catch up the market on time!